The go-xtables from ryongdong

What is go-xtables?

Concepts

Capabilities

Go-xtables is a wrapper for the iptables, ebtables, and arptables utils. It provides full features, extensions and abstractions from Netfilter, making it very convenient to use.

Check out the iptables godoc and ebtables godoc to learn about the 70+ match capabilities, 50+ target capabilities, and 10+ option capabilities.

Matches:

Targets:

Features

Multiple tables(iptables, ebtables, arptables) to support.
Full featured matches, options, watchers and other extensions.
Addtional search.
Chainable pattern.
Dryrun commands to writer.
Log control(inner log, logrus etc.).

Usage

Getting Started

Only accep ssh, http and https ports for incoming traffic

package main

import (
	"log"

	"github.com/singchia/go-xtables/iptables"
	"github.com/singchia/go-xtables/pkg/network"
)

func main() {
	ipt := iptables.NewIPTables().Table(iptables.TableTypeFilter).Chain(iptables.ChainTypeINPUT).MatchProtocol(false, network.ProtocolTCP)

	// allow ssh, http and https
	err := ipt.MatchMultiPort(iptables.WithMatchMultiPortDstPorts(false, 22, 80, 443)).TargetAccept().Insert()
	if err != nil {
		log.Fatal(err)
	}
	// drop others
	err = iptables.NewIPTables().Table(iptables.TableTypeFilter).Chain(iptables.ChainTypeINPUT).Policy(iptables.TargetTypeDrop)
	if err != nil {
		log.Fatal(err)
	}
}

Simple Use

Drop all incoming traffic on specific port

iptables.NewIPTables().
	Table(iptables.TableTypeFilter).
	Chain(iptables.ChainTypeINPUT).
	MatchProtocol(false, network.ProtocolTCP).
	MatchTCP(iptables.WithMatchTCPDstPort(false, 2432)).
	TargetDrop().
	Append()

Accept all incoming traffic from a specific source IP address

iptables.NewIPTables().
	Table(iptables.TableTypeFilter).
	Chain(iptables.ChainTypeINPUT).
	MatchSource(false, "192.168.1.100").
	TargetAccept().
	Append()

Find related rules

rules, err := iptables.NewIPTables().
	Table(iptables.TableTypeFilter).
	Chain(iptables.ChainTypeINPUT).
	MatchSource(false, "192.168.1.100").
	TargetAccept().
	FindRules()

Delete all rules from all tables

iptables.NewIPTables().Flush()

Allow a maximum of 10 connections per minute to enter port 80

iptables.NewIPTables().
	Table(iptables.TableTypeFilter).
	Chain(iptables.ChainTypeINPUT).
	MatchProtocol(false, network.ProtocolTCP).
	MatchTCP(iptables.WithMatchTCPDstPort(false, 80)).
	MatchLimit(iptables.WithMatchLimit(xtables.Rate{10, xtables.Minute})).
	TargetAccept().
	Append()

Mirror traffic to the gateway

iptables.NewIPTables().
	Table(iptables.TableTypeMangle).
	Chain(iptables.ChainTypePREROUTING).
	MatchProtocol(false, network.ProtocolTCP).
	MatchTCP(iptables.WithMatchTCPDstPort(false, 2432)).
	TargetTEE(net.ParseIP("192.168.1.1")).
	Insert()

Deny access from a specific MAC address.

This example uses ebtables. Please note that this rule applies to the linux-bridge, so make sure that the network interface is being hosted by the bridge.

ebtables.NewEBTables().
	Table(ebtables.TableTypeFilter).
	Chain(ebtables.ChainTypeINPUT).
	MatchSource(false, "00:11:22:33:44:55").
	TargetDrop().
	Append()

Real-world scenario

Anti DDOS attack

custom := "SYN_FLOOD"
ipt := iptables.NewIPTables().Table(iptables.TableTypeFilter)
ipt.NewChain(custom)
ipt.Chain(iptables.ChainTypeINPUT).
	MatchProtocol(false, network.ProtocolTCP).
	MatchTCP(iptables.WithMatchTCPSYN(false)).
	TargetJumpChain(custom).
	Append()

userDefined := iptables.ChainTypeUserDefined
userDefined.SetName(custom)
rate := xtables.Rate{1, xtables.Second}
ipt.Chain(userDefined).
	MatchLimit(
		iptables.WithMatchLimit(rate),
		iptables.WithMatchLimitBurst(3)).
	TargetReturn().
	Append()
ipt.Chain(userDefined).
	TargetDrop().
	Append()

Disable PING

iptables.NewIPTables().
	Table(iptables.TableTypeFilter).
	Chain(iptables.ChainTypeINPUT).
	MatchProtocol(false, network.ProtocolICMP).
	MatchICMP(false, network.ICMPType(network.EchoRequest)).
	TargetDrop().
	Append()

Traffic outbound only except ssh port

ipt := iptables.NewIPTables().Table(iptables.TableTypeFilter)
ipt.Chain(iptables.ChainTypeINPUT).
	MatchInInterface(false, "lo").
	TargetAccept().
	Append()
ipt.Chain(iptables.ChainTypeINPUT).
	MatchState(iptables.ESTABLISHED | iptables.RELATED).
	TargetAccept().
	Append()
ipt.Chain(iptables.ChainTypeINPUT).
	MatchProtocol(false, network.ProtocolTCP).
	MatchTCP(iptables.WithMatchTCPDstPort(false, 22)).
	TargetAccept().
	Append()
ipt.Chain(iptables.ChainTypeINPUT).Policy(iptables.TargetTypeDrop)
ipt.Chain(iptables.ChainTypeFORWARD).Policy(iptables.TargetTypeDrop)
ipt.Chain(iptables.ChainTypeOUTPUT).Policy(iptables.TargetTypeAccept)

Note

Compatibility

Starting from Linux kernel version 4.18, nftables became part of the kernel and gradually replaced iptables. Therefore, distributions using Linux 4.18 and higher versions typically use nftables instead of iptables. Since nftables is not fully compatible with iptables, if you still want to continue using go-xtables, it is best to switch to iptables to continue using it when using these distributions.

The following distributions need to pay attention to compatibility:

Debian 10(Buster) and higher versions
Ubuntu 18.04(Bionic Beaver) and higher versions.
Centos 8 and higher versions.
Fedora 18 and higher versions.
OpenSUSE Leap 15.2 and higher versions.
Arch Linux

Contributing

If you find any bug, please submit the issue, and we will respond in a short time.

If you want to contribute new features or help solve project problems, please feel free to submit a PR:

Maintain consistent code style
Submit one feature at a time
Include unit tests with the code you submit

License

Released under the Apache License 2.0

ryongdong / go-xtables Goto Github PK

go-xtables's Introduction